1. Field of the Invention
The present invention relates to a recording liquid, hereinafter simply called ink, for use in recording on a recording material such as paper or plastic film by an ink jet recording process or with a writing tool such as a fountain pen or a felt pen, or in printing on a textile or a non-woven cloth containing synthetic fibers by an ink jet recording process.
2. Related Background Art
Recording by an ink jet recording process is conducted by forming ink droplets through various ink ejecting methods and attaching all or a part of said droplets onto a recording material such as paper, plastic film or textile, and as the ink for such an ink jet recording process, there are already known and employed solutions and dispersions of various water-soluble dyes and pigments in water or in a liquid composed of water and water-soluble organic solvents.
Similar inks are also employed for writing tools such as fountain pens, felt pens, ball-point pens or the like.
Such conventional inks are naturally required to have various performances, but a most prominent requirement is the stability of liquid which ensures no clogging and no deposit at the nozzle, orifice or pen tip of a recording apparatus in case the recording with the ink is interrupted or such recording is not conducted for a prolonged period. This requirement is particularly important in an ink jet recording process utilizing thermal energy among various ink jet recording processes, since deposit formation tends to occur on the surface of the thermal head due to temperature changes. However conventional inks are liable to cause clogging in the nozzle or orifice or deposit on the surface of thermal head of the ink jet recording apparatus, or to form sediment during prolonged storage, because such ink usually contains various additive materials in order to satisfy various requirements such as ink ejecting conditions, shelf life, sharpness and density of recorded images, surface tension and electrical properties, and also because the dyes or pigments employed in such inks contain various impurities, Such drawback of the ink has been one of the reasons of rather low popularity of the ink jet refording process despite of various advantages thereof.